WO2009011698A1

WO2009011698A1 - Drive belt configuration for passenger conveyors

Info

Publication number: WO2009011698A1
Application number: PCT/US2007/073753
Authority: WO
Inventors: George S. Copeland
Original assignee: Otis Elevator Company
Priority date: 2007-07-18
Filing date: 2007-07-18
Publication date: 2009-01-22

Abstract

A passenger conveyor drive assembly (40) includes a step chain (30) and a drive wheel (44) that provides a moving force in a desired direction. A drive belt (42) has a first side that engages the drive wheel so that the drive belt (42) is moved in the desired direction. A second side of the drive belt (42) includes a plurality of teeth (50) for engaging the step chain (30) for moving the step chain (30) in the desired direction. The drive belt (42) has a height (H) and a width (W) that are each transverse to the desired direction. An aspect ratio between the height (H) and the width (W) varies across the width (W) on at least a portion (50, 52) of the drive belt (42).

Description

DRIVE BELT CONFIGURATION FOR PASSENGER CONVEYORS

BACKGROUND [0001] Passenger conveyors such as escalators and moving walkways typically include a set of steps or standing surfaces that carry passengers between opposite ends of the conveyor. The steps are typically arranged in a loop and move in a desired direction of passenger movement.

[0002] For years the arrangement for driving a passenger conveyor included a large sprocket that engaged a step chain, which is associated with the steps. More recently, passenger conveyor drive arrangements including a drive belt have been considered a viable alternative. Example arrangements are shown in the published application numbers WO 2004/063077 and WO 03/099698 and U.S. Patent Nos. 7,137,500; 6,997,302; and 6,457,573. [0003] With the introduction of such drive arrangements, there are various challenges presented to designers of such systems. One challenge has been how to effectively achieve consistent, desired engagement between the drive belt and the step chain. One issue that has not yet been addressed is how to prevent the possibility for lateral shifting or misalignment between the drive belt and other components of the drive assembly.

SUMMARY

[0004] An exemplary passenger conveyor assembly includes a step chain. A drive wheel provides a moving force in a desired direction. A drive belt has a first side that engages the drive wheel for moving the drive belt in the desired direction. A second side of the drive belt includes a plurality of teeth for engaging the step chain for moving the step chain in the desired direction. The drive belt has a height and a width that are each transverse to the desired direction. An aspect ratio between the height and the width varies across the width on at least a portion of the belt. [0005] The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 schematically illustrates selected portions of an example passenger conveyor.

[0007] Figure 2 is an elevational view of an example drive belt. [0008] Figure 3 is an elevational view from another perspective of the example of Figure 2.

[0009] Figure 4 is a cross-sectional illustration including a drive belt consistent with the example of Figure 2.

[00010] Figure 5 is an elevational view of another example drive belt configuration.

[00011] Figure 6 is an elevational view from another perspective of the example of Figure 5.

[00012] Figure 7 is a cross-sectional view including a drive belt consistent with the configuration of Figure 5. [00013] Figure 8 schematically illustrates another example drive belt configuration.

[00014] Figure 9 schematically illustrates another example drive belt configuration.

[00015] Figure 10 schematically illustrates another example drive belt configuration.

DETAILED DESCRIPTION

[00016] Figure 1 illustrates selected portions of an example passenger conveyor

20. A plurality of 22 steps move in a desired direction to carry passengers between landings 24 and 26 at opposite ends of the conveyor 20. The illustration shows an escalator as an example passenger conveyor. Other styles of passenger conveyors such as moving walkways could also be used.

[00017] The steps 22 follow a loop in a generally known manner such that they are exposed for carrying passengers on one side of the loop and hidden beneath a conveyor structure 28 along a return path. A step chain 30, which is also hidden within the conveyor structure 28, is associated with the steps 22. The example step chain 30 comprises a plurality of step chain links 32.

[00018] A conveyor drive assembly 40 includes a drive belt 42 having one side that engages the links 32 of the step chain 30. A drive wheel 44 and an idler wheel 46 establish a loop about which the drive belt 42 travels. The drive wheel 44 is associated with a motor 48 such that the drive wheel 44 provides a force for moving the drive belt 42 in a desired direction that corresponds to the desired direction of movement of the steps 22. The drive belt 42 has one side that engages the step chain links 32 and another side that engages the drive wheel 44 such that the force provided by movement of the drive wheel 44 is imparted to the drive belt 42 and to the step chain 30 to cause the desired movement of the steps 22.

[00019] Figures 2-4 show one example drive belt arrangement. In this example, the drive belt 42 includes a plurality of teeth 50 that engage correspondingly configured teeth on the step chain links 32. As can best be appreciated from Figure 3, teeth 50 are provided on both sides of the belt 42 in this example. The drive wheel 44 has a set of teeth for engaging the teeth 50 facing the drive wheel while the teeth 50 on the opposite side of the belt engage the step chain links 32.

[00020] In this example, a plurality of spacing portions 52 are provided between adjacent teeth 50. The teeth of the drive wheel 44 or the step chain links 32 will be received at the locations of the spacing portions 52 when the components are in appropriate engagement.

[00021] This example includes a centering feature for maintaining a desired lateral alignment between the drive belt 42, the step chain 30 and the drive wheel 44. The drive belt 42 has a height H and a width W that are each transverse to the direction of movement of the drive belt 42. For example, the direction of movement is from right to left in Figures 2 and 3 and into or out of the page in the illustration of Figure 4. Another way of considering the orientation of the height H and width W is that the height H is generally perpendicular to an axis A of rotation of the drive wheel 44 and the width W is generally parallel to the axis A.

[00022] The centering feature in the illustrated example includes a varying aspect ratio between the height H and the width W across the width W on at least a portion of the belt (e.g., H/w is not consistent across the belt 42 when considered in the direction of W). In the illustrated example, the height H varies across the width W of the example belt 42 along selected portions of the belt 42. In particular, in this example, the height H varies across the width W along the outer face on each tooth 50. In this example, a notch 54 is provided on each of the teeth 50. The height H is less at the location of the notch 54 compared to adjacent locations on each tooth 50. [00023] In the illustrated example, each notch 54 comprises two surfaces 56 that are oriented at an oblique angle relative to the axis A of rotation of the drive wheel 44. A lateral profile along a surface 58, which is on the outermost portion of each tooth 50 in this example, varies across the width W of the belt at the location of the crown or outermost edge of each tooth 50.

[00024] As can be appreciated from Figure 4, the drive wheel 44 and the step chain links 32 are provided with a correspondingly configured lateral profile that cooperates with the lateral profile on the surface 58 of the belt 42 for maintaining a desired lateral alignment between the components. The step chain links 32, for example, include a plurality of projections 60 that are at least partially received within the notches 54. The projections 60 in this example have surfaces orientated at an oblique angle relative to the axis A so that there is essentially a mating engagement between the projections 60 and the notches 54.

[00025] The drive wheel 44 has a plurality of projections 62 (or a continuous projection around a circumference of the drive wheel in some examples) that cooperate with the notches 54 on the drive belt 42. The cooperation between the lateral profiles on the drive belt 42 and the step chain links 32 on the one hand and the drive belt 42 and the drive wheel 44 on the other hand prevents relative lateral movement (e.g., from side-to-side in the illustration of Figure 4) between those components.

[00026] Preventing lateral movement between the drive belt 42 and the drive wheel 44, for example, prevents contact between the outside lateral edges of the drive belt 42 and flanges 64 on the drive wheel 44. This avoids wear on the outside edges of the drive belt 42 during passenger conveyor operation. Preventing relative lateral movement between the drive belt 42 and the step chain links 32 ensures desired engagement between them to provide consistent and reliable conveyor operation.

[00027] Figures 5-7 schematically show another example drive belt arrangement. In this example, the drive belt 42 includes a plurality of teeth 50 that are intended to engage correspondingly configured teeth on the step chain links 32 and on the drive wheel 44. In this example, the aspect ratio between the height H and the width W varies along the teeth 50 on one side of the example drive belt 42. In this example, the teeth 50 on the side of the drive belt 42 that engage the step chain links 32 each include an outermost surface 70 and inclined surfaces 72 and 74. In this example, the inclined surfaces 72 and 74 are located at the lateral edges of the corresponding teeth 50. The surfaces 72 and 74 in this example are oriented at an oblique angle relative to the axis of rotation of the drive wheel 44.

[00028] As can be appreciated from Figure 7, the teeth that face toward the drive wheel 44 do not include obliquely oriented surfaces. In this example, the centering feature provided by the varying aspect ratio between the height H and the width W is provided only on the side of the drive belt 42 that engages the step chain 30. In the illustrated example, the step chain links 32 include inclined surfaces 76 and 78 that cooperate with the inclined surfaces 72 and 74 to maintain a laterally centered relationship between the drive belt 42 and the step chain links 32. The mating engagement and cooperation between the varying lateral profiles on the drive belt 42 and the step chain links 32 prevent relative lateral shifting or movement between them during conveyor operation.

[00029] Other configurations of drive belts are possible that incorporate features that provide a varying aspect ratio between a height and a width of a drive belt. Figure 8 shows one example drive belt 42 where a lateral surface profile 80 includes a notch 82. The notch 82 has a generally circular configuration rather than having generally planar surfaces as used in the example of Figure 2-4. A drive wheel 44 or step chain links 32 would have a correspondingly configured protrusion that is at least partially received into the notch 82 to prevent relative lateral movement between them.

[00030] Figure 9 shows another example drive belt arrangement where a lateral profile 90 on at least selected portions of the belt 42 includes a plurality of notches 92 and a plurality of projections 94. In this case, a generally rectangular configuration for the notches 92 is used. A correspondingly configured drive wheel 44 or step chain link 32 has a lateral profile that provides cooperating engagement to prevent relative lateral shifting or movement between the components.

[00031] In the above examples, the centering feature is provided primarily on the teeth or at least some of the teeth of the drive belt 42. In the example of Figure 10, a centering feature resulting in a varying aspect ratio between the height H and the width W of an example drive belt 42 is provided on the spacing portions 52 between teeth 50. In this example, a lateral profile 100 along the spacing portions 52 includes a projection 102. In this example, the projection 102 comprises generally planar surfaces orientated at an oblique angle relative to the axis of rotation of a corresponding drive wheel. In this example, the teeth on the step chain links will have a correspondingly configured recess that at least partially receives the projection 102 during engagement between the drive belt 42 and the step chain links 32. That cooperative relationship ensures desired lateral alignment between the components during operation of the conveyor drive assembly.

[00032] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.

Claims

I claim: 1. A passenger conveyor assembly, comprising: a step chain; a drive wheel for providing a moving force in a desired direction; and a drive belt having a first side that engages the drive wheel for moving the drive belt in the desired direction and a second side comprising a plurality of teeth for engaging the step chain for moving the step chain in the desired direction, the drive belt having a height and a width that are each transverse to the desired direction and an aspect ratio between the height and the width, the aspect ratio varying across the width on at least a portion of the belt.

2. The assembly of claim 1, wherein the aspect ratio varies across the width on each of a plurality of periodically spaced portions of the belt.

3. The assembly of claim 2, wherein each of the plurality of portions is on a corresponding one of the teeth.

4. The assembly of claim 2, wherein each of the plurality of portions is on a section of the belt between two of the teeth.

5. The assembly of claim 1, wherein at least one of the first or second sides of the belt has a lateral profile that varies across the width on the at least a portion of the belt.

6. The assembly of claim 5, wherein the varying lateral profile is on the first side and the drive wheel has a correspondingly configured lateral profile, the varying lateral profile of the belt and the correspondingly configured lateral profile cooperating to prevent relative movement between the belt and the drive wheel in a direction transverse to the desired direction.

7. The assembly of claim 5, wherein the varying lateral profile is on the second side and the step chain has a correspondingly configured lateral profile, the varying lateral profile or the belt and the correspondingly configured lateral profile cooperating to prevent relative movement between the belt and the drive wheel in a direction transverse to the desired direction.

8. The assembly of claim 5, wherein the first and second sides each include a lateral profile that varies across the width on the at least a portion of the belt and wherein the drive wheel and the step chain each include a correspondingly configured lateral profile for preventing relative lateral movement in direction transverse to the desired direction between the drive belt and the drive wheel and between the drive belt and the step chain.

9. The assembly of claim 1, wherein the drive belt includes at least one notch on the at least a portion of the belt.

10. The assembly of claim 9, wherein each of the teeth includes at least one notch.

11. The assembly of claim 1 , wherein the drive belt comprises at least one surface on the first or second side that is oriented at least partially at an oblique angle relative to an axis of the drive wheel such that the aspect ratio varies along the at least one surface.

12. The assembly of claim 11, wherein the drive belt comprises a second surface oriented at least partially at an oblique angle relative to the axis of the drive wheel such that the aspect ratio varies along the second surface.

13. The assembly of claim 12, wherein the at least one surface and the second surface are on lateral edges of the belt and inclined toward each other.

14. The assembly of claim 11, wherein at least one of the drive wheel or the step chain comprises at least one surface oriented at a corresponding oblique angle such that the surfaces oriented at the oblique angles cooperate to prevent relative lateral movement between the drive belt and the at least one of the drive wheel or step chain in a direction transverse to the desired direction.

15. The assembly of claim 1, wherein the drive belt comprises at least one raised projection on the at least a portion of the belt.

16. The assembly of claim 14, wherein the drive belt comprises a plurality of spacing portions between adjacent ones of the teeth, each of the spacing portions includes at least one raised projection.

17. The assembly of claim 1, wherein the drive wheel has a rotation axis, the height is generally perpendicular to the axis and the width is generally parallel to the axis.

18. The assembly of claim 1 , comprising an idler wheel arranged such that the drive belt follows a loop around the drive wheel and the idler wheel.